DE1047419B - Process for the production of foams containing urethane groups - Google Patents

Description

GERMAN

It is known to produce foams from peroxy compounds, polyisocyanates and water with the use of activators and emulsifiers. Depending on the type and amount of the starting materials used, elastic or rigid foams of different specific weights are obtained. Elastic foams produced by the known method have z. B. at a density of 35 kg / m ³ a compression hardness that is 40 to 80 g / cm ² at 40% compression. For some areas of application, however, it is desirable to obtain foams with very high softness and correspondingly low compressive strength. Such particularly soft foams are suitable, for. B. for upholstery purposes, as powder sponges or bandages, as lining material for clothing purposes and in general for the textile industry.

It has been found that elastic foams containing urethane groups can be easily produced from peroxy compounds, polyisocyanates and water with a low static hardness in all requirements, if the reaction components are reacted in the presence of the following compounds:

1. Carbonic acid esters, pyrocarbonic acid esters and orthocarbonic acid esters. Specifically, dimethyl pyrocarbonate, generally alkyl pyrocarbonate, may be mentioned, Diethyl carbonate, glycol carbonate or ethyl orthocarbonate.

2. Acetals, such as acetaldehyde dialkyl acetal, malondialdehyde tetraalkyl acetal, also formalities.

3. Ketals, e.g. B. acetone dialkyl ketals.

4. acyliminoalkyl ethers, e.g. B. acetiminoethyl ether. All these compounds mentioned disintegrate under

the reaction conditions of the foaming in compounds, especially in alcohols and amines, soft hydrogen compounds reactive with NCQ groups exhibit. The disintegration is presumably either due to the exothermic foaming process caused increased temperature of the reaction mixture or hydrolysis by the water contained in the reaction mixture or to the presence of the activators which catalyze the foaming reaction or to an interaction attributable to the factors mentioned. As further cleavage products can also Inert gases, such as carbonic acid or nitrogen, which have no effect on the foaming process, still occur have an adverse effect.

Foam bodies based on polyester isocyanate are already available with the use of monomeric methylol compounds, soft gaseous formaldehyde split off, produced. The procedure thereby effected

for making urethane groups
containing foams

Applicant:

Paint factories Bayer Aktiengesellschaft, Leverkusen-Bayerwerk

Dr. Günther Loew, Cologne,

Dr. Wilhelm Thoma, Leichlingen,

and Dr. Hermann Bernhard, Cologne-Stammheim,

have been named as inventors

additional gas development enables a saving of what is otherwise required for the production of carbon dioxide Diisocyanate or provides foams of reduced density. The physical properties however, the foam bodies are not influenced by these additives.

The polyurethane foams are also produced in a manner known per se. Under Polyhydroxy compounds contain hydroxyl groups linear or branched, optionally isocyanate-modified polyesters and / or polyethers to understand that may still have foreign atoms in the chain, or the hydrogenation products of carbon oxide-ethylene copolymers.

As polyisocyanates, for. B. 1,2,4-tolylene diisocyanate, 1,2,6-tolylene diisocyanate or a technical one Mixture of the two, 1,4-phenylene diisocyanate, 1,5- naphthylene diisocyanate, tripfrenylmethane - 4,4 ', 4 "-triisocyanate, diphenylm'ethane-4,4'-diisocyanate and Find dimethyldiphenyl-4,4'-dirsocyanate use.

In general, 0.5 to 1.5 mol of diisocyanate for every 17 g of the polyhydroxy compound are used for foaming deformed OH groups are used, plus the 0.5 to 10% required for foaming Water and, if necessary, emulsifiers (0.5 to

809 700/572

10%) and accelerators (0.1 to 4%), e.g. tertiary amines, are required.

According to the invention, compounds of the type mentioned above are now also used. These Components are used in amounts from 0.1 to 20 "Zo, preferably 1 to 3%, added to one of the other starting components or else during the Foaming of the components added separately. _,:

The present process not only allows foams of particularly high softness to be produced, but also, depending on the type and amount of the additive used, foams with reduced densities to obtain. In particular, the use of pyrocarbonic acid alkyl esters enables a reduction the density of the finished foams and thus the production is particularly easier and soft foam body.

The effect of the additive to be used according to the invention is illustrated by the following examples further explained.

These foamable reaction mixtures are once without addition and once with the addition of 2 parts of diethyl pyrocarbonate to a), 2 parts of diethyl pyrocarbonate to b), 5 parts of malondialdehyde tetraalkyl acetal foamed to c) and 2.3 parts of acetiminoethyl ether to d).

The resulting foams show the following mechanical values for elongation at break (%) and for the compressive strength at 40% compression fe / cm *):

example 1

The following mixture components are used to produce urethane-containing groups in a known manner Foams made:

a) 100 parts of polyester from 16 moles of adipic acid,

-16 moles of diethylene glycol,

1 mole of trimethylol propane, 37.8 parts of tolylene diisocyanate
"Activator mixture, consisting of

3 parts of adipic acid ester of the N-di-

ethylethanolamine 2 "diethylammonium oleate 1" sulfonated castor oil 2.8 "water
0.2 "paraffin oil

b) 100 parts of polyester from 16 moles of adipic acid,

16 moles of diethylene glycol,

1 mole of trimethylolpropane, 37.5 parts of tolylene diisocyanate
7.3 "Activator mixture, consisting of

0.5 parts permethylated diethylene

triamine

1.5 "diethylammonium oleate 0.5" sulfonated castor oil 4.5 "water
0.3 "Pafafföl

c) 100 parts of polyester from 16 moles of adipic acid,

16 moles of diethylene glycol,

1 mole of trimethylolpropane, 45.5 parts of tolylene diisocyanate
6.9 "Activator mixture, consisting of

0.5 parts permethylated diethylene

triamine

1.5 "diethylammonium oleate 1.0" sulfonated castor oil

3.4 "Water
0.5 "paraffin oil

d) 100 parts of polyester from 16 moles of adipic acid,

16 moles of diethylene glycol,

1 mole of trimethylolpropane, 38.3 parts of tolylene diisocyanate
7.2 "Activator mixture, consisting of 1.2 parts of dimethylbenzylamine

1.5 "Diethylammonium oleate 2.0" sulfonated castor oil 2.2 "water

0.3 "paraffin oil.

Foam fracture
strain Compression hardness a) without addition
with addition
b) without addition., ..,
with addition
c) without addition
with addition
d) without addition
with addition 118
- 152
204
310
120
166
184
319 75
30th
40
17th
55
40
61
39

25th

Example 2

100 parts of a polyester composed of 16 moles of adipic acid, 16 moles of diethylene glycol, 1 mole of trimethylolpropane are mixed with 54 parts of tolylene diisocyanate and 10 parts of an activator mixture consisting of 3 parts Bis (N-diethylethanolamine) adipate, 2 parts of diethylammonium oleate, 1 part of sulfonated castor oil, 2.8 parts Water, 0.2 parts of paraffin oil, with the addition of 10 parts of diethyl carbonate, foamed in a known manner.

The addition of diethyl carbonate results in a foam with significantly higher absorbency received than without this addition.

40

Example 3

From 100 parts of a polyester made from 16 moles of adipic acid, 16 moles of diethylene glycol, 1 mole of trimethylolpropane, 48.5 moles of tolylene diisocyanate, and 7.5 moles of an activator mixture consisting of 1 part of diethylaminoethylmorpholine, 1 part of diethylammonium oleate, 2 parts of sulfonated castor oil , 3 parts of water, 0.5 part of paraffin oil, becomes a. Obtained foam with a density of 35 kg / m ³ .

The addition of 4.5 parts of dimethyl pyrocarbonate to the foamable reaction mixture reduces the density to 26 kg / m ^s .

Example 4

Made from 100 parts of a poly (O and S) mixer from thiodiglycol and butanedioxäthylglykol, 38.5 parts of tolylene diisocyanate, 7.5 mol of an activator mixture, consisting of 1.2 parts of dimethylbenzylamine, 1.5 parts of diethylammonium oleate, 2.0 parts sulfonated castor oil, 2.5 parts of water, 0.3 part of paraffin oil, with the addition of 2 parts of pyrocarbonic acid diethyl ester a foam is produced which, through the addition of the pyrocarbonic acid ester, has a lower density and greater softness than would have been expected without this addition.

Claims (1)

5 6 Claim: carbonic acid esters ^ acetals, ketals or acyl Process for the production of urethane groups ent- iminoalkyläthern implemented. retaining foams made of polyoxy compounds, Polyisocyanates and water in the presence of Accelerators, characterized in that 5 publications under consideration: the reaction components in the presence of German patents No. 860 109, 913 474, Carbonic acid esters, pyrocarbonic acid esters, ortho- 953 561. © 809 700/572 12.58